Energy recovery device

ABSTRACT

An energy recovery device particularly for heating or industrial systems that entail the combustion of products, comprising a tubular element, which is arranged at a flue or stack and has a coil which is perforated along its extension. The coil is connected to a delivery tube for the treatment water for scrubbing the exhaust gases. The tubular element has an outlet for collecting the treatment water, which can be conveyed to a recuperator/heat exchanger. The device makes it possible to reduce the emission of particulates and pollutants into the environment and reduces the temperature of the exhaust gases besides allowing heat energy recovery.

The present invention relates to an energy recovery device.

BACKGROUND OF THE INVENTION

Currently it is known that boilers are used for example to heat waterfor residential and industrial uses.

These boilers are supplied by means of fuels which, by burning, releaseexhaust gases which are expelled by means of stacks or flues.

The combustion that occurs inside boilers inherently producesparticulates and pollutants whose amount can vary as a function of thefuel used.

Moreover, the use of these boilers requires considerable energyresources and has high costs for operation in addition to the drawbackconsisting in the release of a quantity of hot exhaust gases at hightemperature into the environment, which gases still have heat energythat is dispersed into the environment, altering the surroundingbioclimate.

SUMMARY OF THE INVENTION

The aim of the present invention is to solve the above-mentionedtechnical problems, eliminating the drawbacks of the cited backgroundart, by providing a device which makes it possible to reduce emissionsof particulates and pollutants and to reduce the temperature of theexhaust gases released from flues and simultaneously recover part of theheat energy of the exhaust gases.

Within this aim, an object of the invention is to allow improvement ofthe energy balance of industrial heating systems by lowering theiroperating costs.

Another object is to obtain a device that is effective, structurallysimple, has low manufacturing costs and can be provided withconventional known systems.

This aim and these objects, as well as others which will become betterapparent hereinafter, are achieved by an energy recovery device,characterized in that it comprises a tubular element, which is arrangedat a portion of a flue or stack, provided internally with at least onecoil, which is closed at one end and is perforated along its extension,provided with a duct for feeding water for scrubbing the exhaust gases,said tubular element having an outlet for collecting the treated water,which can be conveyed to a recuperator/heat exchanger.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the invention will becomebetter apparent from the following detailed description of a particularbut not exclusive embodiment thereof, illustrated by way of non-limitingexample in the accompanying drawings, wherein:

FIG. 1 is a partially sectional perspective view of a device accordingto the invention in a horizontal layout;

FIG. 2 is a partially sectional view of the device, taken along adiametrical plane;

FIG. 3 is a partially sectional front view of the device arrangedvertically.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the exemplary embodiments that follow, individual characteristics,given in relation to specific examples, may actually be interchangedwith other different characteristics that exist in other exemplaryembodiments.

Moreover, it is noted that anything found to be already known during thepatenting process is understood not to be claimed and to be the subjectof a disclaimer.

With reference to the figures, the reference numeral 1 designates anenergy recovery device, consisting of a hollow tubular element 2, whichis elongated and preferably has a substantially cylindricalcross-section with a preferably flat top 2 a, which has, proximately toa first end 3 a and a second end 3 b, a preferably frustum-shapedtapering portion 4 a, 4 b for connection to a first opening and a secondopening 5 a, 5 b that have a preferably circular cross-section,respectively for inflow and outflow.

The first openings 5 a, 5 b are connected to a portion of a flue orstack, designated by the reference numeral 6, so that the flow ofexhaust gases 7 a that enters through the first opening 5 a passesthrough all of the tubular element 2 and exits through the secondopening 5 b, providing processed exhaust gases 7 b.

Inside the tubular element 2 there is at least one coil 8, whichconsists of at least one single tube arranged on a horizontal planeproximate to the top 2 a.

The coil 8 has a third closed end 9 a, which is arranged proximately tothe first opening 5 a, and a fourth end 9 b, which is arrangedproximately to the second opening 5 b and is connected to a deliverytube 10 for the treatment water 11 used to scrub the exhaust gases thatpass through the tubular element 2.

The water 11 that is present inside the coil 8 exits from a series offirst holes 12 formed along the entire surface of such coil that isdirected at least toward the bottom 13 of the tubular element 2. Theposition of the third and fourth ends 9 a, 9 b can be inverted asregards their arrangement.

Moreover, the tubular element 2 has, at the bottom 13 and preferably ina region that is adjacent to the second opening 5 b, a second hole 14with which an outlet 15 is associated so as to be able to convey thescrubbing water 11 to a recuperator/heat exchanger, which is not shown.

The operation of the device is as follows.

When the burner starts to operate, for example the burner of the boiler,the exhaust gases that originate from combustion are guided into thestack or flue, and along their path they pass through the device, whichis preferably arranged horizontally, and are thus scrubbed beforeexiting into the atmosphere.

When the burner is turned on, a pump is in fact actuated which drawswater 11 from the recuperator/heat exchanger and conveys it along thedelivery tube 10 until it reaches the coil 8.

The water 11 flows through the coil, along its entire length, exitingthrough the first holes 12 arranged below said coil: a shower of dropsis thus formed which, in falling, passes through the flow of exhaustgases that pass through the tubular element.

The amount of water used to spray the exhaust gases and the pressure ofthe exhaust gases are adjusted and balanced so as to avoid causing anyproblems of pressure or negative pressure to the combustion.

Moreover, the pump continues to operate and therefore draw water as longas the burner is operating: shutdown of the burner is in fact followedby the arresting of the pump within a few seconds.

More precisely, the water in this manner is able to lower thetemperature of the exhaust gases, which is harmful for the environmentand which without the device is approximately 70/90° C. if it exits fromcondensation boilers and approximately 120/400° C. if it exits fromboilers which are of the non-condensing type or from ovens or dryers.

Further, the water is able to capture a substantial fraction of thesuspended particulates, which are thus guided and conveyed with thetreated water into the outlet to the recuperator/heat exchanger.

In another embodiment of the invention, shown in FIG. 3, the device 101is arranged vertically and the vertical tubular element 102 isinterposed between the flue or stack 106.

Advantageously, the part of the flue 106 that is adjacent to the firstopening 105 a is arranged along an axis that is inclined with respect tothe longitudinal axis of the tubular element 102.

The tubular element 102 is provided internally with at least one coil108 consisting of at least one single tube and can be extracted, sincethe first and/or second ends 103 a, 103 b are removable.

The coil 108 extends inside the tubular element 102 until itapproximately skims its internal lateral surface 116, forming a seriesof circular turns which are supported by a double comb-like lockingmeans 117 composed of two pairs of linear flanges 118 a, 118 b, whichlie opposite each other and have a series of seats for the placement andsupport of tube portions that constitute the coil 108.

The locking means 117 is fixed to the tubular element 102 by means ofscrews 119, which pass through suitable holes provided in said tubularelement and, once unscrewed, allow the simultaneous extraction of thelocking means 117 and of the coil 108 by means of a handle 120, whichcan be gripped by a user since it is arranged transversely at the upperend of the locking means 117.

The coil 108, closed at a third end 109 a, has first holes 112 providedboth on the surface directed toward the first end 105 a and on thesurface directed toward the inner lateral surface 116 of the tubularelement 102.

The fourth end 109 b is connected to a delivery tube 110 for the waterused to scrub the exhaust gases, which enter through the first opening105 a.

As regards the outlet 115 of the water that filters the exhaust gases incountercurrent, it is arranged below, and contiguously to, the end ofthe flue 106 that is connected along an inclined axis to a port 106 aadjacent the first opening 105 a, so as to be arranged in axialalignment with the tubular element 102.

The operation of the invention is the same as the preceding one: in thisembodiment, the shower of drops passes through the exhaust gases incountercurrent, scrubbing them and lowering their temperature, with aconsequent rise of its own temperature.

Simultaneously, the film created by the water along the walls recoversthe heat of the exhaust gases and captures and directs the dustparticles that are present in the exhaust gases to the outlet of thedevice.

In practice it has been found that the invention has achieved the aimand objects cited above, a device having been obtained which, byscrubbing the exhaust gases, allows the elimination of a substantialfraction of the particulates and pollutants from said gases and at thesame time allows a strong reduction in the output temperature of saidexhaust gases, increasing the temperature of the scrubbing water, whichcan be conveyed to a recuperator/heat exchanger for heat recovery.

The materials used, as well as the dimensions that constitute theindividual components of the invention, may of course be selected by theskilled person so as to be the most pertinent according to specificrequirements.

The various means for performing certain different functions need notcertainly coexist only in the illustrated embodiment but can be presentper se in many embodiments, including embodiments that are notillustrated.

The characteristics indicated as advantageous, convenient or the likemay also be omitted or be replaced with known equivalents, which willall be within the scope of the appended claims.

The disclosures in Italian Patent Application No. TV2009A000024 fromwhich this application claims priority are incorporated herein byreference.

1. An energy recovery device, comprising: a tubular element, which isarranged at a portion of a flue or stack; at least one coil providedinternally to said tubular element, said coil being closed at one endand having perforations along its extension; a delivery tube that isconnected to said coil for feeding thereto treatment water for scrubbingexhaust gases that pass through the stack, and wherein said tubularelement has an outlet for collecting treatment water, which can beconveyed to a recuperator or heat exchanger.
 2. The device of claim 1,wherein said tubular elongated element has a substantially cylindricalcross-section with first and second ends thereof, a flat top and,proximate to said first and second ends, a tapered portion, which isfrustum-shaped for connection to a first opening and to a secondopening, respectively for inflow and outflow of a flow of exhaust gases,said first and second openings having a circular cross-section.
 3. Thedevice of claim 2, wherein said first and second openings are connectedat respective portions of a flue or stack, so that the flow of exhaustgases that enters through said first opening passes through all of saidtubular element and exits through said second opening, as processedexhaust gases.
 4. The device of claim 3, comprising a delivery tube fortreatment water that is usable to scrub exhaust gases that pass throughsaid tubular element, said at least one coil being provided inside saidtubular element and consisting of at least one single tube that isarranged on a horizontal plane proximate to said top, said coil having athird coil closed end which is arranged proximate to said first opening,and a fourth coil end, which is arranged proximate to said secondopening, said fourth coil end being connected to said delivery tube. 5.The device of claim 4, comprising a series of first holes formed alongan entire coil surface directed at least toward a bottom of said tubularelement, said coil being suitable for arrangement with said third andfourth ends in reversible arrangement, the treatment water that is fedin said coil exiting from said series of first holes.
 6. The device ofclaim 5, wherein said tubular element has, at said bottom and further ina region that is adjacent to said second opening, a second hole, with anoutlet associated thereto which is suitable to convey the treatmentwater to a recuperator or heat exchanger.
 7. The device of claim 2,arranged vertically, with said tubular element, arranged interposedvertically between flue or stack parts, said tubular element having apart thereof that is adjacent to said first opening that is providedwith a port having an axis that is inclined with respect to alongitudinal axis of said tubular element.
 8. The device of claim 7,wherein said tubular element is provided internally with said at leastone coil that is mounted so as to be extractable therefrom, said atleast one coil consisting of at least one single tube, said first and/orsecond ends of the tubular element being removable, said coil extendingradially within said tubular element until the coil skims an innerlateral surface of the tubular element, forming a series of circularturns, said turns being provided with and supported by a locking means,said coil being further closed at a third end thereof and having firstholes formed both on a surface of the coil that is directed toward saidfirst end of the tubular element and on the surface of the coil that isdirected toward said inner lateral surface of said tubular element. 9.The device of claim 8, having a fourth end provided with and connectedto a delivery tube for feeding of treatment water used to scrub exhaustgases that enter through said first opening, and an outlet provided fortreatment water that filters exhaust gases in countercurrent, saidoutlet being arranged below and contiguously to an end of the flue,which is connected, along said inclined axis, to said port adjacent saidfirst opening, so as to be arranged in axial alignment with said tubularelement.